I also think of sexual orientation as an irrelevant category for some characters, as long as they can get somebody they find reasonably attractive (which can be a pretty low bar related to availability) to engage in one or more sexual acts the character is interested in. People in this category for me include Jayne (Firefly), Vila (Blakes7) and Eleanor (The Good Place).

That is to say, if Jayne thinks Simon wants to suck Jayne's cock, despite knowing that it is a terrible idea, Jayne will not try to talk Simon out of it. Vila thinks that voluntary sexual activity of any kind is not only better than coerced sexual activity, it's better than DIY (and more interesting than most alternative diversions available). Eleanor's magic hoo-hah wants what it wants.